Gennady Golovkin had been targeted as the next big thing in boxing. He might be that already.

The unbeaten middleweight champion from Kazakhstan couldn’t have looked much more impressive than he did Saturday night en route to an eighth-round TKO over Curtis Stevens of Brooklyn at the Garden Theater.

Golovkin, also known as Triple-G, retained his WBO and IBO titles and improved to 28-0, while recording his 25th knockout before a crowd of 4,618. Stevens’ record dropped to 25-4. Golovkin dropped Stevens in the second round with a thunderous left hook and continued to apply pressure and inflict damage until Stevens’ corner stopped the bout after the eighth round.

Stevens, of Brooklyn, was game but overmatched. Golovkin threw 794 punches in the fight and landed 293. Stevens connected on only 97-of-303.

“I was able to use my array of punches that we work on in the gym to break in down,” Golovkin said. “He was strong and I was a little cautious of his power. But I … never thought I was in any trouble.”

Stevens was a heavy underdog coming into the fight, though some gave him a puncher’s chance because of his own knockout power. But even the power punches he landed didn’t seem to rattle Golovkin.

Golovkin may have surprised Stevens by standing right in front of him at the opening bell. Stevens had trouble avoiding Golovkin’s stinging left jab, but was willing to exchange.

Curtis Stevens struggles to his feet after being knocked down in the second round.

That strategy was flawed, as exposed by Golovkin’s tremendous second-round left hook, which dropped Stevens flat on his back. Clearly hurt, Stevens struggled to his feet and somehow managed to survive the assault from Golovkin that was stopped by the bell.

Still dazed, Stevens went into a defensive shell in the third round as he tried to regain his senses. Wary of Stevens’ punching power, Golovkin didn’t open up, but stayed content to score with his jab.

Golovkin was a patient predator the rest of the bout. Even when Stevens came off the ropes late in the fourth and began to connect with hooks to the head, Golovkin didn’t seem rattled.

At the end of the sixth, Golovkin rocked Stevens with three straight right hands. With his left eye swelling, Stevens tried to go toe-to-toe with Golovkin in the seventh, unwisely. Golovkin began to land his right hand over Stevens’ left guard, pounding the already swollen left eye shut.

Stevens tried to be brave. But he took a pounding in the eighth round. Golovkin hammered him with thunderous shots to the body and then to the head. Referee Harvey Dock looked as if he wanted to stop the fight. When the bell sounded, Steven’s corner wisely decided their fighter had enough.

“I have nothing to be ashamed of,” Stevens said. “This is not the end for me..” “I’m better than anyone gave me credit for. I’ve shown more in a loss than most people show in a win. This is not the end for me. I will learn from my mistakes and I’ll be back.”

Golovkin, who gave himself a grade of 10, seems headed for a bigger stage and a mega-fight . He has a Feb. 1 date in Monte Carlo against an unnamed opponent.